More than 200 strains of dengue virus (including all four serotypes) have been isolated from children hospitalized in Rangoon, Burma with a diagnosis of dengue hemorrhagic fever or acute fever of unknown origin. Dengue viruses were isolated from liver tissue obtained at autopsy from 3 patients who died of dengue shock syndrome or encephalitis caused by dengue virus. No virus was present in heart blood obtained at the same time as the liver specimens. Dengue viruses also were isolated from several nonfatal cases of encephalitis. Twelve strains of dengue virus were isolated from Aedes aegypti mosquitoes collected in a random sampling of households in Rangoon. Dengue type 2 virus was identified as the etiologic agent of an outbreak in the Seychelles (Indian Ocean). BIBLIOGRAPHIC REFERENCES: Gubler, D.J. and Rosen, L.: Quantitative aspects of replication of dengue viruses in Aedes albopictus after oral and parenteral infection. J. Med. Entomol. 13:469-472, 1977. Kuberski, T.T. and Rosen, L.: A simple technique for the detection of dengue antigen in mosquitoes by immunofluorescence. Am. J. Trop. Med. Hyg. 26:533-537, 1977.